Electrical wall boxes, sometimes called gang boxes, switch boxes, outlet boxes, etc., house electrical service components, such as outlet plugs and switches, which are accessible through a hole in the wall material. The box is typically affixed to a stud inside the wall, and when the wall material is put up, after wiring the box, a hole is cut in the wall material. To cover the edges of the hole cut into the wall material, a wall plate is attached over the outlet or switch by a screw or screws that thread into a threaded feature of the box. For electrical outlets, the plug assembly is screwed to the box features, and a cover plate is then placed over the plug assembly. There are many designs of wall boxes, and they are constructed out of either metal or plastic. Metal wall boxes are typically formed from a stamped section of sheet metal in which screw tabs are formed that bend over the front opening of the wall box (when formed). The screw tabs have a hole formed in them that is threaded to match the thread of a machine screw, typically having size #6-32 threading. The screw tabs are generally flat, and there is no supporting structure behind them. Plastic wall boxes, on the other hand, are molded, and are formed with a boss or ridge in the center of the interior side of the top and bottom ends of the box. A threaded hole is formed in these ridges to receive a screw.
A common problem with both types of wall boxes is that the threads in the metal screw tabs or plastic ridges becomes stripped, and unable to retain screws. These threads can become stripped rather easily because the tabs of metal wall boxes are relatively thin, and have very few threads in the screw hole, while in plastic wall boxes the type of plastic used to keep costs down tends to be friable. As a result, just over-tightening the screw once can strip the threads.
Several solutions have been developed to address this problem with regard to plastic wall boxes. In general, a clip having teeth that dig into the plastic is placed over an end wall of the box, and the clip has a hole in the metal front of the clip that aligns with the screw hole formed in the ridge. The hole in the clip engages the threads of the screw, while the retaining teeth in the clip hold the clip in place. However, given the variety of designs of plastic wall boxes, clips of different dimensions are needed that correspond with the specific dimensions of the various plastic wall box designs. Furthermore, because these clips are unable to sufficiently retain themselves on metal wall boxes, because the teeth of the clips cannot dig into the metal, they are not a solution for metal wall boxes with stripped wall box screw holes.
Therefore, a need exists to overcome the problems with the prior art as discussed above.